The present invention relates to a positive type photoresist composition which is sensitive to radiation such as ultraviolet rays, far ultraviolet rays (including eximer lasers etc.), electron beams, ion beams, X-ray and the like, and more specifically to a novel positive type photoresist composition which is capable of forming resist patterns having excellent adhesion with substrates employed for producing semiconductor devices, LCD (thin-film transistor) and the like.
Conventionally, in the process for producing semiconductor devices such as IC and LSI and liquid crystal display elements such as LCD, fine processing according to a photoetching method has been carried out. In this photoetching method, there is adopted a process in which a photoresist is coated on a substrate, an activated ray such as an ultraviolet ray is irradiated through a mask pattern thereon and the substrate is etched using the resist pattern obtained by developing as a protective film. Further, as the photoresist composition employed in this process, it is known that a combination of an alkali-soluble novolak resin for forming a film and a photosensitive component comprising a quinonediazide group-containing benzophenone type compound is preferable (for example, U.S. Pat. No. 4,377,631, Japanese Unexamined Patent Publication (Kokai) No. Sho 62-35349, Japanese Unexamined Patent Publication (Kokai) No. 1-142548 and Japanese Unexamined Patent Publication (Kokai) No. 1-179147).
Incidentally, in the photoetching method in the preparation of a semiconductor device and LCD, adhesion of the resist pattern and the substrate is important, in order to accurately etch the substrate. If adhesion is bad, the bite amount becomes large at the time of wet etching and short circuit of the pattern occurs, disadvantageously.